Refrigeration system

Abstract

When a guard timer of a compressor ( 141 ) expires, an R2 signal from a control section ( 140 ) of an outdoor unit is turned on (Action I). If a control section ( 120 ) of a freezer unit recognizes from an inside temperature detected by a temperature sensor ( 124 ) that the R2 signal is turned on and a request for a shift to a freezer thermo-on state is raised (Action II), a freezer electromagnetic valve ( 121 ) is opened (Action III). In general, when the electromagnetic valve ( 121 ) is opened, it is supposed that an increase in refrigerant suction pressure is detected by a pressure sensor ( 146 ) and then the compressor ( 141 ) is actuated. However, if an outside air temperature is low, the refrigerant suction pressure remains lower than a predetermined value. Therefore, the control section ( 120 ) actuates a booster compressor ( 131 ) (Action IV) to raise the refrigerant suction pressure of the compressor ( 141 ).

1 . A refrigeration system ( 2 ) for vapor compression refrigeration cycle comprising:
 an operation control means for switching a compressor ( 241 ) between actuated state and suspended state based on a refrigerant suction pressure; and   a reference value changing means for reducing a reference value of the refrigerant suction pressure for judging whether to actuate the compressor ( 241 ) or not when the compressor ( 241 ) is suspended and an outside air temperature is reduced from a predetermined temperature.   
   
   
       2 . The refrigeration system ( 2 ) of  claim 1 , wherein
 the reference value changing means is adapted to reduce the reference value in stages based on the amount of reduction in outside air temperature from the predetermined temperature.